1914-11 - Extensive Improvements on the Dominion Atlantic Railway

[stem]

Thanks to Dara for pointing out this article that is, as it turns out, a very important snapshot of the DAR system from end to end.

I am posting this here and not on Facebook because I expect this article to generate weeks of conversation and editing on the wiki and I don't want the thread lost.

So the article is here on the wiki already. Please take read.

There's so many locations and structures we don't currently have and if we do, the majority don't have dates so this is a wealth of information!

My immediate questions are for a civil engineer type that know bridges.
What are and do we have examples of (like lets create a pictorial glossary):
aboiteau
deck Trusses
lattice girders
concrete rail top culvert
d.t span
d.p.g. span
d.p.s. span
h.d.p.g. span
h.t.g. span
lattice girders
lift span
p.g.d.s spans
pit cattle guard vs surface guard
swing span
truss span
t.t. span

[Sarah Taylor]

An aboiteau is a type of dyke with gravity and pressure controlled automatic drainage gates or check valves that allows water to drain to the sea but keeps seawater from flowing back under the dyke. While maintenance is needed, no attention is required for each change of the tide. See for example https://en.wikipedia.org/wiki/Aboiteau# ... _2D-en.svg

A deck truss bridge is a truss bridge with the roadway/railway on top of the trusses. This allows multiple cross bracing under the roadway/railway which can then be more compact for the same strength as other types. The downside is more clearance above the water or whatever passes underneath is needed. An example: https://en.wikipedia.org/wiki/Truss_bri ... e04_1A.jpg
The second Bear River bridge is shown at: http://dardpi.ca/wiki/index.php?title=F ... idge_3.jpg At the far end is a plate deck girder span, then a deck truss span that swings (swing span), then three 156' truss spans, then two more deck girder spans.

A lattice girder is a type of truss, usually constructed of many small members close together. The first Windsor bridge was a lattice bridge. http://dardpi.ca/wiki/index.php?title=F ... 580207.jpg They are distinguished from other truss bridges by the number of small members and the overlap between them. Other trusses are more open, such as the highway adjacent.

A lattice member is a beam or column made up of smaller pieces in a lattice. These are often seen as part of a larger bridge. An example is the parts of the Bridgetown bridge: http://dardpi.ca/wiki/index.php?title=F ... 0x853).jpg

I believe a concrete rail top culvert is just a small concrete culvert with the rails and ballast laid directly on top - would look like a small concrete bridge. It may or may not have a paved bottom. This is not a common usage. Most cuverts are much lower than the railroadbed

I believe the article abreviation d.t. span is "deck truss span"

D.p.g. span is a "deck plate girder" span. The deck is high, at the top of the girders. https://en.wikipedia.org/wiki/Plate_gir ... Tracks.jpg

H.d.p.g. span is "half deck plate girder" span. The sides are plate girders with the deck about halfway between the top and bottom of the girders. See the part of the RR bridge (where the train is) shown at http://dardpi.ca/wiki/index.php?title=F ... idge_c.jpg Notice the rails arte hidden behind the side of the girders, but at not all the way down to the bottom of the girders.

H.t.g. span is ?? Maybe half truss girder - a truss bridge with the deck about halfway between the top and bottom of the truss. The article cites the Gaspereau Bridge, but the spans there in 2010 were two through trusses and two half deck plate girder spans. Perhaps the half deck spans were done later than 1911. An example on the HSW is http://hswdpi.ca/wiki/index.php?title=F ... idge_4.JPG

P.g.d.s. span is "plate girder deck span"

A surface cattle guard is, I think, like this: https://en.wikipedia.org/wiki/Cattle_gr ... _guard.jpg with no deep pit beneath it. While a pit cattle guard has more space below the rails, as at https://steelcattleguards.com/collectio ... grid-hs-20

A lift span is a moveable bridge that is raised to allow ships to pass beneath.

A swing span is a moveable bridge that rotates about a vertical axis to allow ships to pass to one side or the other.

A truss span is a truss bridge between two piers or abutments. So a multi-span bridge might have say, two abutments, one each end, and three piers (free-standing towers), with five "spans" where a span is the distance between a pair of piers or between a pier and an abutment.

A t. t. span is a "through truss" span, such as at Bridgetown http://dardpi.ca/wiki/index.php?title=F ... 0x853).jpg

Not mentioned in the list is a through girder span such as seen at http://dardpi.ca/wiki/index.php?title=File:DAR0029b.jpg and at http://dardpi.ca/wiki/index.php?title=File:CPR8131d.jpg (same bridge) Note the rails are at the bottom of the girders.

[Dan Conlin]

This is a great source, Dara, thanks again for sharing the link to this very rich particular article. This covers the DAR's golden era of expansion wit CPR investment. Lots of good source material in the other issues I imagine as well. I had seen some of these issues in the Carl Riff collection, and the libraries at Dalhousie University and the Maritime Museum have a few scattered issues, but this is a great run for this publication.

Sarah, Thanks for adding this document to the DAR website with the OCR text. You are correct about the "The Railway and Shipping World" becoming the "Canadian Railway and Marine World". They were the same publication with several name changes starting as The Railway and Shipping world [1898-1905]; the Railway and Marine World [1906-July 1912]; the Canadian Railway and Marine World [1912-1936] and finally as Canadian Transportation [1936-1968].

This from the Worldcat library database: https://dal.on.worldcat.org/search?data ... /976932865

[stem]

Created the Bridge Structure Glossary page to define all the terms found in the article that Sarah filled out for us.
http://dardpi.ca/wiki/index.php?title=B ... e_Glossary

I sent a reply to an email with a link to a C.P.R. standard plan book that had some cattle gates in it. If you missed it here it is:
http://www.cptracks.ca/data/standards/c ... s_1_75.pdf

I will now try to find as many C.P.R. engineering prints as I can that show the types of construction and add those in.

[Dan Conlin]

Sarah's abbreviations are right on the money. Once you know these, the track profiles maps make a lot more sense because these abbreviations are used all over the place. There are also a who series for different types of culverts but I haven't found a good guide to them: Corrugated Metal Pipe Culvert etc.

[stem]

I'm in the process of hypertext linking all the terminology and bridges in the article. I've found some C.P.R. engineering prints of some of the structures and will add them in after that. Very interesting exercise! Really incredible engineering went into railways and the investment made by C.P.R. into the D.A.R. was massive!!

[stem]

There's a couple of definitions yet not described. Could use some civil help here!
d.p.s. span
d.s. span
t.p.g.

[Sarah Taylor]

A t.p.g. is a through plate girder, where the rails are carried low down between the plate girders, such as seen at the Allain River bridge: File:AnnapRoyal 2 (1280x853).jpg

A d.p.s. span is a deck plate swing span, seen at the South Maitland River bridge as shown at the left side in: File:DAR - Shubenacadie Bridge West Bank-2May1987.jpg The axis of swing is above the first "o" in the word "Collection" on the picture.

A d.s. span is probably a deck (girder or plate) swing span. The example given is the bridge at Big Joggins but we have no photograph showing this moveable span. The second South Maitland bridge and the Sissiboo River bridge had similar mechanisms.

[Sarah Taylor]

Some more abbreviations, as used in the 1969 Memorandum of General Information:

r.c.c. "reinforced concrete culvert"

c.s.p.p. "corrugated steel plate pipe" [culvert]. (A more-common abbreviations are c.s.p. (corrugated steel pipe) or c.m.p. (corrugated metal pipe) .) Used for freshwater locations. Even then, C.S.P.P. is not now (2020) used much in Nova Scotia because of relatively short life compared to locations well-away from the ocean.

c.s.s.p. may be "corrugated stainless steel plate" [pipe culvert]. This is noted for the Little Joggins River, which is tidal. The common galvanized corrugated steel pipe quickly fails in salt water or even areas with salty air.

p.t. "pile trestle", also may be t.p.t. "treated pile trestle"

t.l.g - noted for two short spans either side of Kennetcook. These spans are gone. It may stand for "treated lumber girder"

[stem]

Take a look at the track charts I'm uploading and have already linked to some of the bridge pages. Same type of nomenclature although a few differences may shed some light. You can start with the Bear River bridge for example.

http://dardpi.ca/wiki/index.php?title=F ... ridge.jpeg

[Sarah Taylor]

I have looked at the details shown in the 1918 track profile drawings. The details given there do not always match the information given in the magazine article.

For example in the magazine article the Bear River Bridge is said to have "four 156 ft. truss spans, six 100 ft. d.p.g.’s, one 85 ft. d.p.g., one 50 ft. d.p.g. and one 144 ft. swing span." but the track profile has (not in the order in the actual bridge) four 156'9¼" deck trusses (OK), six deck plate girders - length not shown - so likely the 100 foot ones (OK), a deck swing truss 144'6" (OK), a 50' deck plate girder (OK), a 103'3" deck plate girder (the 85' one in the article?) (not OK but close) and a 39' deck plate girder not mentioned in the article (oops).

Neither the article [[http://dardpi.ca/wiki/index.php?title=C ... ic_Railway]] nor the plan [[http://dardpi.ca/wiki/index.php?title=F ... ridge.jpeg]] match the text in the wiki page on the bridge [[http://dardpi.ca/wiki/index.php?title=Bear_River_Bridge]] The wiki page is based on 1913 plans. Those plans might have been preliminary and the actual bridge was different, perhaps based on actual site conditions. The profile of 1918 has in order from west end to east end: deck plate girder 50'1", deck plate girder 103'3", deck truss 150'9¼", deck swing truss 144'6", 3 - deck trusses 156'9¼", 6 - deck plate girders (length not shown), deck plate girder 39'

The Big Joggins River in the article omits a 32'2¼" deck plate girder.

The Little Joggins River in the article omits 104' of trestle compared to the plan.

So I expect when all the profile information is posted we will get a more-correct list of the actual bridges in place in 1918. Of course changes could have been made between 1914 and 1918.

[stem]

Thanks Sarah. Sharp eye there. I think that for the Bear River Bridge can you put the info here on the talk/discussion page so that all know that there's conflicting information that needs to be clarified?

[Sarah Taylor]

I wouldn't say there is conflicting information actually. I would say the 1918 track profile is the most-trustworthy information and earlier (and likely pre-construction) drawings were either superceded by later designs or by actual as-built construction. So we could already change the text on the Bear River Bridge wiki page. I was kind-of waiting for all the profile data to be done before doing each location.

Of course the 1918 drawing is trustworthy as of that date, changes were of course made subsequently at some locations. So the erroneous text would be replaced with 1918 information and noted as such.

Is there a title block on the profile drawing? That would help interpret some of the information. For example what are the vertical and horizontal scales, and what does each grid line mean. (horizontal lines mean vertical elevations) (vertical lines are horizontal distances - often 100 foot is used for horizontal distance, often called "chainage"

I will fix the Bear River Bridge page soon.

[stem]

A little background - Ken McIlvoy was a gentleman who as a consultant helped with the creation of the original VIA service as he had done with AMTRACK. Whilst in Montreal at the C.P.R. offices he asked for any plans or info about the D.A.R. and was given a number of items from photos to plans. Check out his collection as he sent all that to me and I scanned it all in 2009 and then sent it back.

For the Bear River to Digby section the title block is on the Bear River section. The way I received the drawings was in two different forms. Ken obviously got a number of rolls and for most of the rolls, he cut them down to just named locations in 8-1/2" pages and three hole punched them and didn't include the sections in between unfortunately.

But he left one roll reasonably intact and that was the Bear River to Digby section. The title block says mile 40 to 60 (old miles) but it's was only 49 to 60. But I took it to the engineering office and scanned the entire sheet - something like 34" (D Size) and 12 or 14 feet long as I recall @ 400 DPI (I had to send them back to him). This created a file so large in BMP (822 MB) that until I got this computer I was unable to process it. Now that I could process it, I took the original scan and cut them into sections focused on locations but not leaving out any in between detail.

So the bottom line is, the images with 3 hole punches came from rolls that we don't know when the drawings were created. For the section between Bear River and Digby, we know they are 1918. If you were to grab all those sections and put them back together you would see the length of the original scan. I overlapped them just a few inches just in case someone decided to try that.

http://dardpi.ca/wiki/index.php?title=F ... _River.jpg

[Sarah Taylor]

I found the title block with the scales for horizontal and vertical distances.